The present invention relates to the treatment of liquids, including waste liquids. In particular, the present invention relates to an apparatus for mixing or aerating liquids.
Aeration devices used in the treatment of liquid, especially water, are known in the prior art. The aeration devices may be employed to encourage aerobic bacteria in treating wastewater or in treating bodies of water to make the water more potable or more suitable for food production. In addition, the aeration devices are commonly used for ice control purposes.
One type of aeration device known in the art includes a motor located above the liquid being treated and generally mounted to a support structure. A leg extends from the motor below the liquid surface and connects the motor to a submerged propeller. The leg includes a shaft coupled to the motor which drives the propeller and may include an outer housing that surrounds the shaft. An air inlet provided above the liquid surface allows the rotating propeller to draw air into the leg and supply a flow of air to the propeller. For this type of aeration, the quantity of air discharged into the liquid is dependent solely upon air flow created by the rotating propeller.
Airflow-assisted aerators, which augment the air flow created by the propeller, are known in the art. These aerators, however, do not include a blower and a propeller capable of being operated at different speeds while being powered by the same aerator motor, which results in sub-optimal aerator efficiency.
The present invention is an improved aerator that allows for the efficient supply of additional aeration capacity.